The invention relates to a climbing appliance for roping percons up and down using the double rope technique.
Climbing appliances of the described type are used in various fields, e.g. where tree surgery tasks such as treetop consolidation or lopping or work on facades or roofs has to be carried out. A further area of application is moreover in the sport of climbing for belaying purposes. The climbing appliances in said case are used, on the one hand, as a fall protection apparatus but at the same time the appliance is also to be regarded as a specialized appliance for effecting the working method, xe2x80x9cdouble rope climbing techniquexe2x80x9d, hereinafter referred to as xe2x80x9cDRCTxe2x80x9d.
Utilizing the force-reducing xe2x80x9cblock-and-tackle principlexe2x80x9d, with the DRCT climbing and work is carried out using constant rope tightening, which means that each climbing movement is accompanied by a rope movement, which is actively effected by the climber.
Using said permanent rope tightening the most varied positions on a scaled article may be reliably achieved, wherein the belaying of the body to a reversing point (anchoring point) located as high up the scaled article as possible crucially stabilizes the balance of the climber. Once, for example, one of the many and widely varied working positions in tree surgery has been reached, the climbing appliance is required to be always, as after any kind of operation, automatically in a secure holding position. At any time the climber has to be able to effect a finely tuned variation of his position, either by lengthening or shortening the rope line. Without neglecting the rope tightening, a fluent moving-and-securing sequence is to be guaranteed in all planes of a scaled article. It should be emphasized that all of the described features also have to be capable of implementation one-handedly and with the body in any position relative to the appliance. DRCT, which in accordance with the apparatuses known from prior art, which without exception may be implemented by means of so-called clamping knots, about the weaknesses of which it is not intended to go into detail here, is in future to be used upwards and downwards employing the climbing appliance according to the invention and make a substantial contribution with regard to ergonomics, efficiency and safety.
Rope clampo, revolving catch appliances, roping-up appliances, roping-down appliances, arresting shock absorbers, fall arresters, rescue and self-rescue appliances with their features tuned to specific sub-regions of DRCT may be rendered redundant by the appliance according to the invention.
From DE-OS 197 46 294 A1 of the applicant a safety apparatus for roping-up and roping-down operations is known, in which the safety apparatus comprises a housing and at least one clamping jaw clampable against the housing, wherein the rope end, connected to the climber, of the main rope passed over an upper reversing point is firmly connected to the housing and the free end of the same rope, after running through the reversing point, is disposed in a clamping receiver between housing and clamping jaw. In the case of said safety apparatus, an additional belaying rope is fastened to the clamping jaw and conveyed in a receiver, which rune round radially at the outside of the housing and clamping jaw, around both components. The resultant effect is that, given tensile stress upon the belaying rope, the safety apparatus is transferred from a release position for the main rope into a clamping position for the latter. The described safety apparatus has in principle proved successful in many areas of DRCT where dynamic roping-up and roping-down operations are necessary.
A particular property of the safety apparatus is that the connection rope between climber and safety apparatus, which is known as the belaying rope and is responsible for introduction of the braking forces, ensures that, given tensile stress upon the belaying rope, a cancellation of some of the braking force is not possible even in the case of a fully executed release movement. While said feature may be employed in a perfectly positive manner, the effect of maintaining some of the braking force for roping-up may be disadvantageous in that a specific drag has to be overcome when pulling on the climbing rope.
The object of the present invention is therefore further to develop a universal climbing appliance for roping persons up and down having the generic features described initially in such a way that its area of application is extended by also enabling a cancellation of the clamping position when the connection rope between climber and climbing appliance is under tensile stress. The object of the invention is moreover to develop the climbing apparatus in such a way that it may, by virtue of a simple design, be manufactured particularly efficiently and inexpensively and maintenance and repair work on the climbing appliance may easily be carried out.
According to the technical teaching of the invention, the housing of the climbing appliance has, off centre in the outside edge region, a fastening point for a connection rope between climbing appliance and climber. Furthermore, the pivot of the clamping jaw is disposed substantially centro-symmetrically on the clamping jaw and a release rope is fastened to the housing in the opposite outside edge region to the fastening point for the connection rope.
By virtue of the special arrangement of connection rope and release rope combined with the special pivot arrangement of the clamping jaw inside the housing, given tensile stress upon the connection rope the entire climbing appliance automatically rotates. The rotation causes the rope, which extends through the recess between housing and clamping jaw, to be pressed in between housing and clamping jaw in a such a way that said rope is prevented from slipping through any further. A fall of the climber is therefore ruled out the moment the connection rope between climbing appliance and climber is subjected to tensile stress. In the present case the clamping jaw, because of its centro-symmetrical pivot, operates according to the so-called rocking lever principle, this being explained in detail in the description of the drawings below. The effect of the special arrangement of the release rope on the housing of the climbing appliance is that the rotation of the climbing appliance effected as a result of tensile stress upon the connection rope may be cancelled in an approportioned manner even though the connection rope is still under tensile stress. This facilitates operation, particularly during roping-up, because tensile stress upon the main rope fixed in the clamping apparatus, in the situation where the rope line leading to the upper reversing point of the main rope is to be shortened, also leads to rotation of the safety apparatus back into its release position for the main rope, with the result that a variation of the position of the climbing appliance on the main rope is possible even though the connection rope is still being placed under load by the climber. By virtue of the special construction according to the invention, therefore, a roping-up operation may also be effected virtually free of resistance.
In particular, it has proved expedient when the release rope fastened to the housing is accommodated in a sleeve projecting radially beyond the housing. The sleeve accommodated in the housing stiffens the end of the release rope fastened to the housing in a manner which facilitates an extended lever arm for the rotation of the climbing appliance back into the release position. Thus, the release movement may be effected without any great expenditure of force. Furthermore, by using sleeves of differing length a variation of the release resistance is possible in that the release resistance may be increased by a short sleeve or may be particularly reduced by a particularly long sleeve.
A particularly advantageous refinement of the subject matter of the invention moreover comprises the feature that the rope conveyed over the reversing point is fastened to the housing in a suspension apparatus, which is rotatable in longitudinal axis of the rope. Said suspension apparatus may according to a special construction comprise two U-shaped shackles, wherein the parallel limbs of the shackles are fastened in each case to the rope and/or to the housing and wherein the webs connecting the limbs are connected to one another by a hinge. The rotational movement possible within the rope suspension neutralizes twisting of the main rope and frictional resistances of the double rope resulting therefrom.
It has moreover proved expedient when the recess for the main rope extending through the climbing appliance is substantially a cylindrical through-bore cut half out of the housing and half out of the movable clamping law. Said construction, on the one hand, guarantees a reproducible clamping effect and, on the other hand, provides precise guidance of the supporting rope inside the safety apparatus under all operating conditions.
According to a further special refinement of the subject matter of the invention, the clamping jaw at its upper end of the through-bore directed towards the reversing point of the main rope may have a location groove, which extends substantially at right angles to the centre line of the through-bore. The width of said groove is such that it is slightly smaller than the diameter of the main rope extending through the clamping receiver. The effect achieved by said special refinement is an additional braking torque in the event of rotation of the climbing appliance as a result of tensile stress upon the connection rope. This arises from the fact that an extreme rotation of the climbing appliance, besides the clamping of the main rope between housing and clamping jaw in the through-bore, additionally effects a drawing of the main rope into the location groove provided in the clamping jaw. In said case, the special dimensional design of the groove gives rise to an additional braking effect.
It should additionally be mentioned that exchanging the clamping jaw rotatably mounted in the housing allows the use of different diameters of supporting rope in that the sub-region of the through-bore cut out of the clamping jaw is selected so as to be larger or smaller. Furthermore, easy repair of the climbing appliance may be effected by exchanging the clamping jaw, because the clamping jaw itself is to be regarded as the only essential wearing part of the entire climbing appliance.
A special further refinement variant of the invention provides that the rotational movement of the clamping jaw in the housing of the climbing appliance may be limited in terms of its maximum deflection or totally blocked by means of a setting apparatus. Said measure make it possible to effect a fine adjustment of the total braking force of the appliance.